/*
 * Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <stdlib.h>
#include <getopt.h>
#include <memory.h>
#include <stdio.h>
#include <math.h>
#include <iostream>
#include <iomanip>
#include <cuda.h>

using namespace std;

#include "gdrapi.h"
#include "common.hpp"

using namespace gdrcopy::test;

// manually tuned...
int num_write_iters = 10000;
int num_read_iters = 100;
int dev_id = 0;
bool do_cumemcpy = false;
bool use_cold_cache = false;
size_t _size = (size_t)1 << 24;

void print_usage(const char *path)
{
    cout << "Usage: " << path << " [-h][-c][-s <size>][-d <gpu>][-w <iters>][-r <iters>][-a <fn>]" << endl;
    cout << endl;
    cout << "Options:" << endl;
    cout << "   -h              Print this help text" << endl;
    cout << "   -c              Also run cuMemcpy (default: no)" << endl;
    cout << "   -s <size>       Buffer allocation size (default: " << _size << ")" << endl;
    cout << "   -d <gpu>        GPU ID (default: " << dev_id << ")" << endl;
    cout << "   -w <iters>      Number of write iterations (default: " << num_write_iters << ")" << endl;
    cout << "   -r <iters>      Number of read iterations (default: " << num_read_iters << ")" << endl;
    cout << "   -a <fn>         GPU buffer allocation function (default: cuMemAlloc)" << endl;
    cout << "                       Choices: cuMemAlloc, cuMemCreate" << endl;
    cout << "   -C              Use cold cache (default: no)" << endl;
    cout << "                       This option takes effect when cache mapping is used such as on Grace-Hopper." << endl;
}

int main(int argc, char *argv[])
{
    size_t copy_size = 1;
    struct timespec beg, end;
    double lat_us;

    gpu_memalloc_fn_t galloc_fn = gpu_mem_alloc;
    gpu_memfree_fn_t gfree_fn = gpu_mem_free;

    while(1) {        
        int c;
        c = getopt(argc, argv, "s:d:w:r:a:cCh");
        if (c == -1)
            break;

        switch (c) {
            case 's':
                _size = strtol(optarg, NULL, 0);
                break;
            case 'd':
                dev_id = strtol(optarg, NULL, 0);
                break;
            case 'w':
                num_write_iters = strtol(optarg, NULL, 0);
                break;
            case 'r':
                num_read_iters = strtol(optarg, NULL, 0);
                break;
            case 'a':
                if (strcmp(optarg, "cuMemAlloc") == 0) {
                    galloc_fn = gpu_mem_alloc;
                    gfree_fn = gpu_mem_free;
                }
                else if (strcmp(optarg, "cuMemCreate") == 0) {
                    galloc_fn = gpu_vmm_alloc;
                    gfree_fn = gpu_vmm_free;
                }
                else {
                    cerr << "Unrecognized fn argument" << endl;
                    exit(EXIT_FAILURE);
                }
                break;
            case 'c':
                do_cumemcpy = true;
                break;
            case 'C':
                use_cold_cache = true;
                break;
            case 'h':
                print_usage(argv[0]);
                exit(EXIT_SUCCESS);
            default:
                printf("ERROR: invalid option\n");
                exit(EXIT_FAILURE);
        }
    }
    
    size_t size = PAGE_ROUND_UP(_size, GPU_PAGE_SIZE);

    ASSERTDRV(cuInit(0));

    int n_devices = 0;
    ASSERTDRV(cuDeviceGetCount(&n_devices));

    CUdevice dev;
    for (int n=0; n<n_devices; ++n) {
        
        char dev_name[256];
        int dev_pci_domain_id;
        int dev_pci_bus_id;
        int dev_pci_device_id;

        ASSERTDRV(cuDeviceGet(&dev, n));
        ASSERTDRV(cuDeviceGetName(dev_name, sizeof(dev_name) / sizeof(dev_name[0]), dev));
        ASSERTDRV(cuDeviceGetAttribute(&dev_pci_domain_id, CU_DEVICE_ATTRIBUTE_PCI_DOMAIN_ID, dev));
        ASSERTDRV(cuDeviceGetAttribute(&dev_pci_bus_id, CU_DEVICE_ATTRIBUTE_PCI_BUS_ID, dev));
        ASSERTDRV(cuDeviceGetAttribute(&dev_pci_device_id, CU_DEVICE_ATTRIBUTE_PCI_DEVICE_ID, dev));

        cout  << "GPU id:" << n << "; name: " << dev_name 
              << "; Bus id: "
              << std::hex 
              << std::setfill('0') << std::setw(4) << dev_pci_domain_id
              << ":" << std::setfill('0') << std::setw(2) << dev_pci_bus_id
              << ":" << std::setfill('0') << std::setw(2) << dev_pci_device_id
              << std::dec
              << endl;
    }
    cout << "selecting device " << dev_id << endl;
    ASSERTDRV(cuDeviceGet(&dev, dev_id));

    CUcontext dev_ctx;
    ASSERTDRV(cuDevicePrimaryCtxRetain(&dev_ctx, dev));
    ASSERTDRV(cuCtxSetCurrent(dev_ctx));

    ASSERT_EQ(check_gdr_support(dev), true);

    CUdeviceptr d_A;
    gpu_mem_handle_t mhandle;
    ASSERTDRV(galloc_fn(&mhandle, size, true, true));
    d_A = mhandle.ptr;
    cout << "device ptr: 0x" << hex << d_A << dec << endl;
    cout << "allocated size: " << size << endl;

    if (galloc_fn == gpu_mem_alloc)
        cout << "gpu alloc fn: cuMemAlloc" << endl;
    else
        cout << "gpu alloc fn: cuMemCreate" << endl;

    uint32_t *init_buf = NULL;
    uint32_t *h_buf = NULL;
    ASSERTDRV(cuMemAllocHost((void **)&init_buf, size));
    ASSERT_NEQ(init_buf, (void*)0);
    ASSERTDRV(cuMemAllocHost((void **)&h_buf, size));
    ASSERT_NEQ(h_buf, (void*)0);
    init_hbuf_walking_bit(init_buf, size);

    if (do_cumemcpy) {
        cout << endl;
        cout << "cuMemcpy_H2D num iters for each size: " << num_write_iters << endl;
        printf("Test \t\t Size(B) \t Avg.Time(us)\n");
        BEGIN_CHECK {
            // cuMemcpy H2D benchmark
            copy_size = 1;
            while (copy_size <= size) {
                int iter = 0;
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_write_iters; ++iter) {
                    ASSERTDRV(cuMemcpy(d_A, (CUdeviceptr)init_buf, copy_size));
                }
                clock_gettime(MYCLOCK, &end);
                lat_us = time_diff(beg, end) / (double)iter;
                printf("cuMemcpy_H2D \t %8zu \t %11.4f\n", copy_size, lat_us);
                copy_size <<= 1;
            }
        } END_CHECK;

        cout << endl;
        cout << "cuMemcpy_D2H num iters for each size: " << num_read_iters << endl;
        printf("Test \t\t Size(B) \t Avg.Time(us)\n");
        BEGIN_CHECK {
            // cuMemcpy D2H benchmark
            copy_size = 1;
            while (copy_size <= size) {
                int iter = 0;
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_read_iters; ++iter) {
                    ASSERTDRV(cuMemcpy((CUdeviceptr)h_buf, d_A, copy_size));
                }
                clock_gettime(MYCLOCK, &end);
                lat_us = time_diff(beg, end) / (double)iter;
                printf("cuMemcpy_D2H \t %8zu \t %11.4f\n", copy_size, lat_us);
                copy_size <<= 1;
            }
        } END_CHECK;

        cout << endl;
    }

    cout << endl;

    gdr_t g = gdr_open_safe();

    gdr_mh_t mh;
    BEGIN_CHECK {
        // tokens are optional in CUDA 6.0
        ASSERT_EQ(gdr_pin_buffer(g, d_A, size, 0, 0, &mh), 0);
        ASSERT_NEQ(mh, null_mh);

        void *map_d_ptr  = NULL;
        ASSERT_EQ(gdr_map(g, mh, &map_d_ptr, size), 0);
        cout << "map_d_ptr: " << map_d_ptr << endl;

        gdr_info_t info;
        ASSERT_EQ(gdr_get_info(g, mh, &info), 0);
        cout << "info.va: " << hex << info.va << dec << endl;
        cout << "info.mapped_size: " << info.mapped_size << endl;
        cout << "info.page_size: " << info.page_size << endl;
        cout << "info.mapped: " << info.mapped << endl;
        cout << "info.wc_mapping: " << info.wc_mapping << endl;

        // remember that mappings start on a 64KB boundary, so let's
        // calculate the offset from the head of the mapping to the
        // beginning of the buffer
        int off = info.va - d_A;
        cout << "page offset: " << off << endl;

        uint32_t *buf_ptr = (uint32_t *)((char *)map_d_ptr + off);
        cout << "user-space pointer: " << buf_ptr << endl;

        cout << "use cold cache: " << (use_cold_cache ? "yes" : "no") << endl;
        if (use_cold_cache && info.mapping_type != GDR_MAPPING_TYPE_CACHING) {
            cerr << "ERROR: Cold cache has no effect on other mappings except cache mapping" << endl;
            exit(EXIT_FAILURE);
        }

        // gdr_copy_to_mapping benchmark
        cout << endl;
        cout << "gdr_copy_to_mapping num iters for each size: " << num_write_iters << endl;
        cout << "WARNING: Measuring the API invocation overhead as observed by the CPU. Data might not be ordered all the way to the GPU internal visibility." << endl;
        // For more information, see
        // https://docs.nvidia.com/cuda/gpudirect-rdma/index.html#sync-behavior
        printf("Test \t\t\t Size(B) \t Avg.Time(us)\n");
        copy_size = 1;
        while (copy_size <= size) {
            int iter = 0;
            lat_us = 0;
            if (use_cold_cache) {
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_write_iters; ++iter) {
                    // Simulate GPU writing the data written by CPU. When cache
                    // mapping is used, the cache lines will be moved to GPU.
                    // The next access by CPU will cause the cache lines to
                    // move back to CPU (cold cache). gdr_copy_to_mapping will
                    // pay this cost.

                    // We use sync memops. The memset is considered done by the
                    // time cuMemsetD8 returns.
                    cuMemsetD8(d_A, 0, copy_size);

                    gdr_copy_to_mapping(mh, buf_ptr, init_buf, copy_size);
                    SB();
                }
                clock_gettime(MYCLOCK, &end);

                lat_us += time_diff(beg, end);

                // Measure the cost of cuMemsetD8 and remove that from the
                // total latency.
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_write_iters; ++iter) {
                    cuMemsetD8(d_A, 0, copy_size);
                }
                clock_gettime(MYCLOCK, &end);

                lat_us -= time_diff(beg, end);
            }
            else {
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_write_iters; ++iter) {
                    gdr_copy_to_mapping(mh, buf_ptr, init_buf, copy_size);
                }
                clock_gettime(MYCLOCK, &end);

                lat_us += time_diff(beg, end);
            }
            lat_us = lat_us / (double)iter;
            printf("gdr_copy_to_mapping \t %8zu \t %11.4f\n", copy_size, lat_us);
            copy_size <<= 1;
        }

        // gdr_copy_from_mapping benchmark
        cout << endl;
        cout << "gdr_copy_from_mapping num iters for each size: " << num_read_iters << endl;
        printf("Test \t\t\t Size(B) \t Avg.Time(us)\n");
        copy_size = 1;
        while (copy_size <= size) {
            int iter = 0;
            lat_us = 0;
            if (use_cold_cache) {
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_read_iters; ++iter) {
                    // Simulate GPU writing the data to the shared buffer. When
                    // cache mapping is used, the cache lines will be moved to
                    // GPU.  The next access by CPU will cause the cache lines
                    // to move back to CPU (cold cache). gdr_copy_from_mapping
                    // will pay this cost.

                    // We use sync memops. The memset is considered done by the
                    // time cuMemsetD8 returns.
                    cuMemsetD8(d_A, 0, copy_size);

                    gdr_copy_from_mapping(mh, h_buf, buf_ptr, copy_size);
                    LB();
                }
                clock_gettime(MYCLOCK, &end);

                lat_us += time_diff(beg, end);

                // Measure the cost of cuMemsetD8 and remove that from the
                // total latency.
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_read_iters; ++iter) {
                    cuMemsetD8(d_A, 0, copy_size);
                }
                clock_gettime(MYCLOCK, &end);

                lat_us -= time_diff(beg, end);
            }
            else {
                clock_gettime(MYCLOCK, &beg);
                for (iter = 0; iter < num_read_iters; ++iter) {
                    gdr_copy_from_mapping(mh, h_buf, buf_ptr, copy_size);
                }
                clock_gettime(MYCLOCK, &end);

                lat_us += time_diff(beg, end);
            }
            lat_us = lat_us / (double)iter;
            printf("gdr_copy_from_mapping \t %8zu \t %11.4f\n", copy_size, lat_us);
            copy_size <<= 1;
        }

        cout << "unmapping buffer" << endl;
        ASSERT_EQ(gdr_unmap(g, mh, map_d_ptr, size), 0);

        cout << "unpinning buffer" << endl;
        ASSERT_EQ(gdr_unpin_buffer(g, mh), 0);
    } END_CHECK;

    cout << "closing gdrdrv" << endl;
    ASSERT_EQ(gdr_close(g), 0);

    ASSERTDRV(gfree_fn(&mhandle));

    return 0;
}

/*
 * Local variables:
 *  c-indent-level: 4
 *  c-basic-offset: 4
 *  tab-width: 4
 *  indent-tabs-mode: nil
 * End:
 */
